一、项目结构
一个学生类。当中学生类中能够包括Course类对象
使用Maven管理项目的能够加入fastjson的坐标：
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.4</version>
</dependency>二、数据对象转化为Json字符串
GenerateJson.java代码标识转化为json字符串
（1）将学生对象转化为json，当中学生中包括Course对象
@Test
public void testSimpleJSON(){
Student stu = new Student("xuliugen", "nan", "123123", "100");
Course course = new Course("JAVA", "xiaobin", "100");
stu.setCourse(course);
String json = JSON.toJSONString(stu);
System.out.println(json);
}{
"course":{
"coursename":"JAVA",
"coursescore":"100",
"courseteacher":"xiaobin"
},
"password":"123123",
"score":"100",
"sex":"nan",
"username":"xuliugen"
}（2）将一个单独的实体对象转化为json
@Test
public void testListJSON(){
JSONTest jt1 = new JSONTest("xuliugen", "nan");
JSONTest jt2 = new JSONTest("xieyan", "nv");
List<JSONTest> li = new ArrayList<JSONTest>();
li.add(jt1);
li.add(jt2);
String jsonstr = JSON.toJSONString(li);
System.out.println(jsonstr);
}[{"name":"xuliugen","sex":"nan"},{"name":"xieyan","sex":"nv"}]（3）将包括多个相似于（1）中的实体对象转化为json
@Test
public void testMulJSON(){
Student stu = new Student("xuliugen", "nan", "123123", "100");
Course course = new Course("JAVA", "xiaobin", "100");
stu.setCourse(course);
Student stu2 = new Student("xieyan", "nan", "123123", "100");
Course course2 = new Course("music", "qwe", "100");
stu2.setCourse(course2);
List<Student> stuList = new ArrayList<Student>();
stuList.add(stu);
stuList.add(stu2);
String json2 = JSON.toJSONString(stuList);
System.out.println(json2);
}[
{
"course":{
"coursename":"JAVA",
"coursescore":"100",
"courseteacher":"xiaobin"
},
"password":"123123",
"score":"100",
"sex":"nan",
"username":"xuliugen"
},
{
"course":{
"coursename":"music",
"coursescore":"100",
"courseteacher":"qwe"
},
"password":"123123",
"score":"100",
"sex":"nan",
"username":"xieyan"
}
]三、解析json数据到实体对象
（1）解析上述（1）中学生中包括Course的对象
[{"name":"xuliugen","sex":"nan"},{"name":"xieyan","sex":"nv"}] @Test
public void testParseSimpleJSON(){
String json = "[{\"name\":\"xuliugen\",\"sex\":\"nan\"},{\"name\":\"xieyan\",\"sex\":\"nv\"}]";
JSONArray jsonArray = JSON.parseArray(json);
String str = jsonArray.getString(0);
JSONTest jsonTest = JSON.parseObject(str,JSONTest.class);
System.out.println(jsonTest.getSex());
}{
"course":{
"coursename":"JAVA",
"coursescore":"100",
"courseteacher":"xiaobin"
},
"password":"123123",
"score":"100",
"sex":"nan",
"username":"xuliugen"
}（2）因为仅仅有一个对象，解析例如以下：
@Test
public void testParseStudentIncludeCourseJSON() {
String json = "{\"course\":{\"coursename\":\"JAVA\",\"coursescore\":\"100\",\"courseteacher\":\"xiaobin\"},\"password\":\"123123\",\"score\":\"100\",\"sex\":\"nan\",\"username\":\"xuliugen\"}";
Student stu = JSON.parseObject(json,Student.class);
System.out.println(stu.getPassword());
}（3）将上述中的（3）当有多个上述的对象的时候，解析例如以下：
[
{
"course":{
"coursename":"JAVA",
"coursescore":"100",
"courseteacher":"xiaobin"
},
"password":"123123",
"score":"100",
"sex":"nan",
"username":"xuliugen"
},
{
"course":{
"coursename":"music",
"coursescore":"100",
"courseteacher":"qwe"
},
"password":"123123",
"score":"100",
"sex":"nan",
"username":"xieyan"
}
]解析例如以下：
@Test
public void testParseListStudentIncludeCourseJSON() {
String json = "[{\"course\":{\"coursename\":\"JAVA\",\"coursescore\":\"100\",\"courseteacher\":\"xiaobin\"},\"password\":\"123123\",\"score\":\"100\",\"sex\":\"nan\",\"username\":\"xuliugen123\"},{\"course\":{\"coursename\":\"music\",\"coursescore\":\"100\",\"courseteacher\":\"qwe\"},\"password\":\"123123\",\"score\":\"100\",\"sex\":\"nan\",\"username\":\"xieyan\"}]";
JSONArray jsonArray = JSON.parseArray(json);
String str = jsonArray.getString(0);
Student stu = JSON.parseObject(str, Student.class);
System.out.println(stu.getUsername());
}